The surgical anatomy and operative surgery of the middle ear

THE SURGICAL ANATOMY AND OPERATIVEIT is not my purpose to give here a didactic and complete description of the middle ear and its adnexa, but to bringinto prominence the various landmark

-UNIVER%

THE SURGICAL ANATOMY AND OPERATIVE

SURGERY OF THE MIDDLE EAR

SURGEON TO THE ROYAL EAR HOSPITAL, ETC.

REBMAN, LIMITED

129, SHAFTESBURY AVENUE, CAMBRIDGE CIRCUS

1901

INTRODUCTION

THE subject of the following monograph is one of immense

importance to the otologist, and any investigation by a surgeon

of so wide a reputation and such varied experienceas the author

is of especial value.

In translating the monograph I have endeavoured to render

M. Broca's workinto appropriate English idiom, but at the same

time tofollow his language and style as closely as possible

Where necessary, I have added footnotes, especially when theopinion expressed in the text has in any way differed from thatcurrent in this country

MACLEOD YEAESLEY.

10, UPPER WIMPOLE STREET, W.,

July18, 1901.

676784

PAGE

I SURGICAL ANATOMY 1

THE ATTIC AND ADITUS 15

II. OPERATIVE PROCEDURES 18

I. OPENING THE MASTOID 18

II. OPENING THE MASTOID AND TYMPANUM 25

in. STACKE'S OPERATION 31

IV. OPENING THE MASTOID, THE TYMPANUM AND THE

V. OPENING THE CRANIUM BY THE MASTOID ROUTE 35

THE ATLAS - 39

THE RELATIONS OF THE SINUS AND THE ANTRUM 47

THE FACIAL NERVE - - 51

THE SURGICAL ANATOMY AND OPERATIVE

IT is not my purpose to give here a didactic and complete

description of the middle ear and its adnexa, but to bringinto

prominence the various landmarks thanks to which the surgeon

can attain certain success; to lay stress upon the structure ofthe mastoid and the arrangement of its cells; andto state withprecision the situation ofthe organs,which to treat with caution

is indispensable Too often, indeed, good surgeons, whilstoperating, wound the lateral sinus or thefacial nerve Hence

it is necessary not only to know where to attack, but where to

let alone: it is necessary to know exactly what to avoid

What makes these studies so complex is that in this regionanatomical relationsvary with the age ofthe subject, andconse-quently importantoperative deductions vary also (see figures).

ExternalForm Themastoid processissituated at theinferiorpart of the outer surface of the temporal bone, behind theauditory meatus Slightly oblique forwards and downwards, it

is usually conoidal in form. Its anterior border, thick and

rounded, is distinctly vertical; its posterior border is, in theadult, inclined about 45 degreesdownward andforward Behind

its superior part is the mastoid foramen, through which passes

an emissaryvein ofvariable size, generally communicating withthe lateral sinus

The bulk of themastoid depends partlyon the strength ofthe

muscles inserted in its tip, and thus it is natural that it should

bein general proportiontothesize of the bonesof theindividual,

as Lenoir proved at the Anthropological Museum; but, on the

1

example, which are nearly full size in the foetus at term It is

theexo-cranial part of the petrous bone whose development is

thusretarded

Of thethreeportionsofthe temporal bone squamous,petrous,tympanic two really take part in the formation of the mastoid

process: the squamous above and in front, the petrous behind

and below The junction of the two parts forms the mastoid suture, .represented by sms in the figures ; this shortsuture on the external surfaceof the process,leaving the parietal

squamo-slope, joins the anterior border above the tip.

I do not believe, despite the assertion of Chipault, that this

notch of termination can be felt through the softparts, but onadrymastoid the suture is visible at all ages in the form of agroove more or less irregular and unequal. Inlaying bare thebone it can be easily recognised, because at its level, especially

in somewhat aged subjects, the instrument has some difficulty

in raising the periosteum, and the shreds of the latter leave awhite line.

The squamous portionofthemastoid formsatriangle,bounded

by this suture, the meatus, and a horizontal ridge the mastoid ridge (csm in the figures) which prolongs behind theposterior root of the zygomatic process (linea temporalis of

supra-German authors). This ridge, more or less prominent indifferent subjects, is always appreciable, even in the child.

It is an important landmark, for it is generally situated a little

below the floor ofthe middle fossa of thecranium, sometimes at

a level with, very rarely above, this floor ; so that if one attacksthe bone with the gouge resting below it, one isnearly certainnot to penetrate the cranial cavity unwittingly

Onthe outer surface of the process anotherirregularityisseen,

which furnishes the surgeon with one of the best of landmarks,

the spine of Henle, represented by H in the figures (spina

supra-meatumof the Germans) It is a moreorless rugoseand

promi-nent situated behind and above the

Surgical Anatomy 3

quadrant of the meatus, below the origin of the supra-mastoidridge This lamellais incurved nearly concentrically to thecir-

cumference of the meatus, but its upper extremity is a little

more anterior than is theinferior.

Occasionallythis spine scarcely projects at all; on the other

hand, to find it in laying bare the process, it is often necessary

to use the instrument as ifone wished to penetrate the superior segment of thebony meatus It isbounded in front by

postero-a vpostero-asculpostero-ar zone, which varies greatly in different subjects This

is sometimes a simple chink, like a scratch, within the borders

ofwhich appear onlymicroscopic foramina Very often in front

of the lamella a very deep cup-shaped depression is found,pierced by foramina (Figs 24 and 37) ; sometimes it is even alarge hole (Fig. 38).

Whatever may be said, this spine does not appear to spring

from the tympanic bone. This is the distinct result of theresearches of 0 Lenoir aswell as of those of Ch.Millet Inwell-

preserved skulls theposterior boundary of the tympanicring is

always seen to sink obliquely above and inside into the funnel of

the auditory canal, and stop separated from the spine bya spacethat is always distinguishable, often considerable (Figs 37 and

38) Further, comparative anatomy is conclusive In oldhorses the tympanic ring is practically closed completely; the

two extremities of the ring are, in regard to one another, not

separated by a millimetre; but in this animal, exactly at thespot where the spine of Henle is found in man, a specialosseous point can be seen, separated very distinctly from the

tympanicring, with which it is not united in the least. Inthegorilla the spine ofHenle, usuallyverydistinct,clearlyseparated

from thetympanic ring, is situated just above the circumference

of the bony meatus

Ido not believe, therefore,that the spine is connected with the

tympanic ring, but I would rather connect it, with 0 Lenoir,with an osseous point known in embryology under the name of

epitympanal (Geoffrey Saint-Hilaire), its special factorof

import-ance being the above-mentioned vascular foramina, which seem

ofvery distant morphological or even operative interest.*

* See Fig.34 for details, and p. 53 for explanatory text Figs. 25and 26

(explanatory text, p 45) are sections prepared to show the connections of

theseforaminaandthe limitrophic cells of themeatus Whentheforamina

arelargeandnumerous,there are points therewherethemucousmembrane

passage of puseasy. Intheyoungchild this corresponds to thespongyspot

12

4 Surgical Anatomy

The spine of Henle, when it exists, is a valuable operative

landmark; but is it constant, and can one count upon it?Certain authors contest its constancy, but all those who have

really studied the subject give it a great value Kiesselbach

found it 82 times out of 100 and Schultze 109 times in 120

Mypupil and friend Lenoir,in an abstract of 100 adult skulls in

a perfect state of preservation, has onlyverified the absence ofthe spinein one single instance, and even thenthe anomaly was

unilateral, thus making oneabsence in 200mastoids In twenty

cases the spine was slightlymarked, but yet recognisable by a

practised eye and finger.*

The distinct conclusion is, then, that we are right in

depend-ing uponthis bony landmarkin the adult Isit the sameinthechild? To determine this question M. Lenoir has examined

fifteen crania (thirty mastoids) of children of different ages atthe Anthropological Museum; he has at the same time studiedthedistinctness ofthe supra-mastoid ridge and of the squamoso-mastoid suture

Heconcluded that this landmark cannot bemuch reliedupon

in a regular manner below four years of age, and it isonly from

ten years that it can be considered as certain to be always tinct ; the same may be said of the supra-mastoid ridge

dis-But in infants a very characteristic appearanceis to be seenon

the surface of the bone over the cortex which hides the antrum

Behind the spineof Henle,as Ihavepointedout, severalvascular

foramina are to be found, more orless numerous and deep, and

thence they are very often continued above the bony meatusandbelow the supra-mastoid ridge (Figs 24, 37, 38). In the infantthese vascular openings transform this region into a perfect

sieve, which can be seen verywell in operating upon the livingsubject, in the form of a depressible, friable lamina In therecent cadaver a regular purple rounded spot is seen, like a

sanguineous effusion inthe bony substance Ihave always seenwhich is discussed on p. 5 and Fig. 39, and the antrum is then covered

simplybya thin perforated lamina. These foramina haveseveral connections

with the persistent petro-squamosal sinus. The displacement of the

limi-trophic cells,whichbecomepostero-external,is explainedonp.41.

* Thereis certainlyadifference of opinion regarding theconstancyof the supra-mastoid spine orspineof Henle. Probablythe author is in the main

correct in givingit as nearlyalways present. Ihave,however,metwith a

good manycases,both in the dead and living subjects, inwhichitwasbut

very feebly marked The fossa which accompanies it is, on the contrary,

alwayspresent, although itmayat times be ameredimple,andIhave fore always laid more stress uponthe presence of thissupra-mastoid'fossa

there-than the spine

Surgical Anatomy 5this spot in the foetus of more than eight months and inchildren

under two years. This spongyspot (Fig 39) is situated exactly atthe level of the antrum It is at first above themeatus/then

above andin front; much later the vascularzone coincideswiththe posteriorpart of the spine of Henle, andfrom thattime thespine becomesa landmark These landmarkschange,therefore,

in proportion as the subject grows older, for they move below

and behind in a circumference concentric to the auditorymeatus

Structure The temporal bone is hollowed out by cavitiescontinuous with the pharynxby the medium of the Eustachian

tube and lined with mucous membrane From the functionalpoint of view, the most important of these cavities is the

tympanum, which containsthe auditory ossicles. To this drum

is attached a veryvariable arrangement of cells, which renderthe mastoidprocess and the neighbouringparts pneumatic

Around these air cells isa cortex, of which the surgeon must

recognise the density at the level of the outer surface of theprocess In the young child this shell is thin and but little

resistant, but in the adult this does not hold, and thevariations

of thickness and of hardness are very considerable The

sections (children, Figs 20-23, 29 and 30; adults, Figs 47, 48,

51) show thatif, in places, the cortex is scarcelyone millimetrethick, in other subjects one cannot break through less than 6millimetres to reach the largest cells (Fig 51) It is useful to

remember that, in the course of an operation, a hard mastoid

must not be mistaken for an eburnatedprocess.

The system of cavities surrounded by this cortex is, asI have

said, very variable; or rather, it is. composed of two parts: theantrum, constant in its presence and pretty nearly so in its

position; the cells, very different in various subjects, which

radiate around it and can be divided,accordingtothe partof the

temporal bone inwhich theyare situated, intosquamous, mastoid,

andpetrous. It is on account ofthese variations that, according

to their richnessin cells, Zuckerkandl has divided mastoids into

pneumatic (36'8 p. 100), mixed (43*2 p. 100) and diplo'ic orsclerosed, that is to say, unprovided with cells (20 p. 100)

And what tends to complicate these individual differences is

that in the first place similar mastoids, diplo'ic or sclerosed at

one point, present at another a well-developed cell group, andinthe second place, amongst these variations, some are congenital,others acquired,and that progressive eburnation, bordering

6 Surgical Anatomy

'

sclerosis,' of themastoid is often the result of chronic tions in thetympanum.

suppura-These cells are inconstant; development demonstrates that

they are the annexes of the antrum It is, therefore, in thestudy of the antrum thatwe ought properly to begin the pure

anatomical description of this region. But the operator must

knowthe organs in the order of superposition inwhich he will

find them, that is tosay, from the surface to the deeper parts;

therefore I commence by speaking of the secondary cells.

The mastoid cells, properly speaking, that is to say the cells

which occupy the mastoid portion of the temporal bone, are

nothing as regards the group which bears this name in currentsurgical language; unless, indeed, the squamous and petrous

cells are added to them, at least for the most part. The only

true mastoid cells are situated below a horizontal line passingnear the junction ofthe upper third with the lower two-thirds ofthe meatus This is the group of special cells, and when these

cells are important, it is among them that the largest cavitiesare found, as the cells in Figs 53, 54, 55 These figures show,further, that among the mastoid and squamous cells is a perfectbuttress which appears to mark, deep down, the remains of the

mastoido-squamous suture

These cells, the most easyto reach by operation when they

are well developed, are those by which one endeavours pally to distinguish mastoids into pneumatic,diploic and mixed;

princi-no external indication allows us to recognise their importance

beforehand, and, for example, one can conclude nothing from

the bulk of the mastoid Figs. 53 and 54 show verylarge cells

in a small mastoid from an old man Which proves nothing,

moreover, forthe squamous andpetrous cells,which are of greatinterest pathologicallyandanatomically. The mastoidcells are,

to speak truly, only annexes of the others

Thesquamous cellsare situated in the part of the squamous

bone which contributes tothe formation of the posteriorwall ofthe external auditory rneatus Certain among them form, incontactwith the meatus, the group of cellsbordering themeatus

(limitrophic cells). These are prolonged sometimes above the

meatus, and even in front of it, into the root of the zygoma,above the temporo-maxillaryarticulation.* InFigs 53, 54, 55,

* It is

important to remember these cells in thezygomainopening themastoidin children, as theymayotherwise mislead one into believing that

antrum when

Surgical Anatomy 7 squamous cells of small size are seen; those in Fig 52 are, on

the contrary, largeand wellformed In general, they are small,butit is necessary to remember their existence,fortheir opening

is indispensable for an operation to be complete

The petrous cells occupy the base of the process, above a

horizontal linepassing through the junction of the upper third

and the lower two-thirdsofthe meatus Above theymayextend

fairly far (Figs. 53, 54); in frontthey are limited by the archedpremastoid lamina (Fig 51, p. 59),whichwill be further studied;

behindthey extendtowardsthelateralsinus, in frontofwhichthey

may extend (Figs. 52, 53, and 54), almost to touch the occipital.

It is by the studyof horizontal sections (Figs 20-23, 27-29,

47, 48, 51), that these petrous cells are accurately seen These

sections show, further, the various relations which they may

have with the lateral sinus, from which they are separated

by a compact plate, sometimes thick (Fig 51), sometimesvery

thin (Figs 47, 48). They also show that petrous cells can bepresent behind the antrum for the lengthoftheposterior surface

of the petrous bone (Fig 51, C").

When one studies the mastoid anatomically in the cadaver,

and not by operation on the living subject, it is by excavating

by degrees, after having opened all the preceding cells, that the

antrum is at last reached Often enough in about the thirdcase in the adult one opens into these cells by a very distinctcanal, with a superficial openingclearly defined, which might becalled theexternal aditus Thisorifice is occasionallyvery easy

to see, and from that time theantrum can be found with ease;

on the contrary, it may be hidden by a convex septum, and if

thecell which is bounded behind bythis septum is spacious, one

may fancy that the antrum has been opened. But a carefulsearch in the superior anterior angle of this false antrum withthe point of the probe fails to find the narrow opening of theaditusad antrum leading to the tympanum ; and by excavating

belowand under this lamella the antrumis reached at the level

of the spine of Henle

In thus hollowing out the mastoid, the order of the formation

of the cells is followed backwards After the tympanum, which

is the primordial cell, the antrum is the first of the accessory

others

In the foetus, the mastoid process does not exist ; in the born child but yet the antrum is found

new-Surgical Anatomy

in them, prolonging the attic behind into the thickness of

the petrous bone, and the dimensions of this antrum arealready nearly as considerable as they will be later on in theadult.*

From thisantrum, by a progressive aereolation around it, the

air cells, which gradually invade the other partsof the temporal

bone, proceed At birth, contrary to what has been said, thereare nearly always some present, which is easy to demonstrate

by a procedure which Farabceuf has taught us: a little mercury

is poured into the tympanum of anew-born child, then the bone

is turned over and lightly shaken; the metal collects in the

antrum and, if the bone be scraped with a bistoury behind the

tympanic ring, very distinct vacuoles filled with the liquid aregenerally to be found

The squamoso-mastoid suture opposes, for a'

certain time, abarrier to the advance ofthe cells, which donot pass it untilthe

first yearhas elapsed ; and, much later, the trace of this suture

is generally found in the interior of the process in the form of awall bounding one or several cells, exactly beneath the furrow

which marks it on the surface (Figs 53, 54)

The antrum being themost constant cell inthe whole system,

it is particularly important to study its surgical anatomy, inorder to determine:

1 Its depth

2 Its relationswith appreciable external landmarks

3 Its exact relations with neighbouring organs of which it is

necessary to be careful

1. The Depth of the Antrum This question, a cardinal onefrom the operative point of view, has received various solutions

The answer depends greatly on the age of the subject, and at an

equal age, varies in different individuals

In the foetus at term and in infants under one year, the depth

of the antrum is veryslight; it is only from 2to 4 millimetres,

and there is nothing easier than to penetrate this cavity by

scratching with a bistoury at the spongy spot previouslydescribed

In the yearswhich followbirth,theantrum becomesgradually

deeper, but with individual differences for which it is impossible

to establish anylaw Thus, in a subjectof three years(Fig 45)

* Cheatle has

pointed out that the antrum was thusdeveloped with the

tympanum, and suggested in consequence that it should in future be called

'

the tympanic receptacle,' the name'

mastoidantrum'

being misleading.

Surgical Anatomy 9

theantrum was already 10millimetres deep, and only 4'5

milli-metres in a child of five (Fig 46). On another occasion Ihavefound an antrum situated 11 millimetres from the surface in asubject aged three and a half years. In the adult one meets

withsimilar variations, and it is necessaryto knowthemaximum

depth at which theantrum maybe searched forwithout danger;

in ourseries, in two subjects (Figs. 46and48) oftwenty-five and

forty-five years, the antrum was 16 and 15 millimetres deep;but intwo very old subjects, sixty and seventy-five years, it was

25 and 29 millimetres (Figs. 50 and 52).

I am therefore obliged to conclude that, if a rule is laid down

to stop if any cavity is not found at 5 or6 millimetres (Politzer),

at 20 millimetres (Noltenius), at 25 millimetres (Schwartze,Chipault)^ one risks missing an antrum which possibly is

present The more one fails to find it, the more one shouldact with caution, but one ought not to give up too soon The

practical interest of this discussion is not very great, for inchronic otitis, when openingis decidedly indicated, one has only

to broach the cavities another way, by attacking the tympanumfirst by Stacke's method; and in acute mastoiditisthe rarefying

osteitis contributes to make the work easier. But that is notconstant, and then it is sometimes necessary to have a perfectfaith in clinical diagnosis and anatomy in order to reach the

antrum

2. Positionofthe Antrum in Relation to External Landmarks

The antrum really possesses in the previously-mentioned

land-marks spongy spot in young children, supra-mastoid ridge,

squamoso-mastoid suture, spine of Henle relations capable of

giving thesurgeon almost perfect safety.

Ineednotrevert at lengthtothe spongyspot in young children '

By working at this levelwith a curette or with the point of abistoury the antrum is very quickly reached. This spot is

situated above and behindthe meatus

When this ceases to be appreciable, the anatomical

deter-mination becomes less easy; but even then it is not very

difficult.

To begin with, we knowthat, whatever be the age of the

sub-ject, theantrum is situated beloiv the supra-mastoid ridge, above

andin front of the squamoso-mastoidsuture. These two lines, I

know, are not always distinct, especially inthe child; but when

they are present it is the rule in the adult they are valuablefor the delimitation of thefield of

io Surgical Anatomy

Theconstant landmarks are (I) the spine of Henle; (2) when

this spine is notpresent, the superior pole ofthe ellipseformed by

the meatus.*

Ifwe suppose (which we are practically permitted to do) thatthe antrum is displaced, we can conclude that, situated just

above the arch ofthe bony meatus before term, the centre of the

antrum in the foetus at term is above and a little behind thispoint; then it is displaced gradually downward and from before

backward Near the age of ten years it is on the horizontaltrack by the spine of Henle, and fromthis moment it no longerbecomes lower, but keeps directly behind at a distance, nearly

fixed, of 7 millimetres, which it reaches at adolescence

Before passing tothe studyof the relationsof theantrumwith

certain organs which it is importantto treat with respect, I will

say a few wordsregarding the aditus ad antrum, the canalwhich

joins the antrum and thetympanum. This description will beabridged; it will be completedwhen I come to speak of the topo-graphical anatomy of the drum, and ofthe attic in particular

The aditus is a canal which, in theadult, is 3 to 5 millimetreslong, 3 millimetres high, and 3 to 4 millimetres deep. In thefigures it will presently be seen in section (AD) occupied by a

probe, and thus it will be shown that its direction and formdepend upon the age of the subject, and vary with the position

culty, and goes right acrossto the other end of the drum, the

orifice of the Eustachian tube (Fig 42). The deeper theantrum

descends behind the meatus, the higherin theanterior wall is it

necessary to search for the aditus, and thence the canal, which

continues to tend towards the attic that is to say, above the

tympanic ring descends no more; at first it even ascends a

little, tolightlycurve with an inferiorinternal concavity, asintheadult it cannot be directly catheterized by a straightinstrument

of any size.

On the arch of the outer wall of the aditus more or less

numerous small cellsopen Itsthresholdrests onthe horizontal

* As I have pointed outin a previous footnote, the supra-ineatal fossa is

alwayspresentwhen the spine of Henleis absent,althoughitmaybe butamere

Surgical Anatomy

portion of theaqueduct of Fallopius; on its inner wall projectsthehorizontal semicircularcanal Itsupperwall isformed bythetegmen tympani, a plate always very thin, often deficient, pierced

bythe branchesofthemeningealvessels; vestiges ofthe internalpetro-squamosal suture can be seen here (Figs. 16 to 19).

3. Deep Eelations of theAntrum and Aditum Across the roof

of the tympanum the aditus is in very close relation with the

temporal fossa of the cranium and the temporal lobe of thebrain

The three organs which must always beremembered inting are (1) the horizontal semicircular canal; (2) the facial

opera-nerve; (3) thelateral sinus

(a) The horizontal semicircularcanal issituated just behindtheinner wall of the aditus It is against thiswall that the pro-tector must be placed toprevent anyinjury; otherwise the canal

is surrounded by a solid eburnated shell, which of itself offers astrong resistance to instruments. Besides, whether it is that I

have never touched it, or that its injury is no inconvenience, I

havenever had to record any troubles due to an impairment of

the internal ear in my operations

(b) Thefacial nerve, leaving by the hiatus Fallopii, is directedoutwards, parallel to the axis ofthe petrous bone, on a course of

about 10millimetres; then it is bent to passvertically down, toleave the cranium at the level of the stylo-mastoid foramen It

is the horizontal part of the facial canal, with the elbow, thatpasses under the threshold of the aditus, protected only by alamella, sometimes extremely thin Often enough, as repre-sentedin Fig 49, the horizontal portionofthecanalisbetter pro-

tected, and much more internal

Thevertical part of the canal descends inthe anteriorregion

of the mastoid, behindtheposterior limb of the tympanic ring

There it passes through a compact lamina known to modern

authors under the name of thearcliedpremastoid lamina(marked

byp in Fig 51). In this vertical part the facial is only separated

from the foramen for the jugular vein by a band of tissueordinarily fragile, and hollowed by large pneumatic cells

(Fig 49)

The result of this anatomical study is that if,in the child, we

seek the antrumwhere it is, so to speak, too high, the opening

is absolutely without danger to the facial nerve; and if, when

the antrumis exposed, we demolish the outer wallof the aditusthe nerve is from making

theinstrument parallel to the canal One therefore acts withgreat caution when a certain depth is reached On an average,

Noltenius estimates the distance separating the spine of Henle and the facial to be 13 millimetresin depth But the knowledge

of an average has not any interest for us; the dangerous zone

will without doubt occasionally be much more extensive,but it is

sufficient to be able to have cases in which it is reduced to

10 millimetres in order that we may be on our guard at this

depth at once and quickly The best precaution to take is not

to open too low In operating at the height of the spine of

Henle, and in working towardsthe aditus, one passes above the

elbow of the facial, and once the aditus comes into view one is

masterof the situation, asthen thewhereabouts of thefacial is

known

(c) The lateralsinus is, of the three organs, theonewhichmost

engrosses us,especiallybecauseit ismenacedinthemost common

operation the simple opening of the mastoid so that it is very

often wounded by the surgeon. This accident is explained in

part, and in part only, by the anatomical variations soimportant

to be recognised ; and this restriction once admitted, it is pedient to acknowledge without further delay that it is nearly

ex-always due to the clumsiness of the operator. This assertiondoubtless appears somewhat sweeping to surgeons who have

involuntarily opened the sinus, but I can only express it after

having openedmore than 300 mastoids without ever havingmet

with such an accident, save in one instance where, the bony

excavation having ended, I perforated the venous canal with aprobe in exploring a purulent pocket which surrounded it. If,

then, there exists an anatomical arrangement such that thesurgeon, in finding the antrum, is fated to come upon the sinus,

my operative statistics prove that it must be very rare But it

suffices that it may be possible to make it necessary to study it

in detail.*

* Tliis

opinion is contrary to that expressed by Lake in theJournal of

That observer made number

Surgical Anatomy 13

Certain authors make a great to-do about the fact that thegroove for thelateral sinus, situated at a very variable distance

behind the external auditory meatus,may be found very closeto

this canal in horizontal projection; it mayeven be reported infront to be '

procident

'

to such a degree as tobe in frontof the

antrum Thus, Hessler has reported four cases of caries ofthe

middle earwith the sinus situated in front of the antrum; after

he had passed through 2 to 4 millimetres of spongy bone, hereached the dura mater and wounded the sinus, which forced

him tointerrupt the operation without havingreached the focus

of the caries; and Hessler notes twelve analogous cases in the

literature.

To suppose thatin these observations no error of

interpreta-tion orof operative technique has entered an objectionwhich

is liableto occur in observations made on the living subject

one can only conclude that the anatomical arrangement which

they have demonstrated is possible, but by no means frequent.

Frequency can only be established by the anatomical study of a

numerous'series. Now, Hartmann, in 100 preparations, onlyfound two in which trephining would touch the sinus; in his

memoir, so exact from an anatomical point of view, Eicard saysthat he has only met, in horizontal section of the petrous,with one single case where such danger existed,and yet he adds,

'

in thisextreme case, a distance of 12 millimetresstill separatedthe sinus from the posterior wall of the external auditorymeatus.'

Now, what dothese anatomical facts,from the operative point

ofview, signify? Nothingmuch, and the followingisthe reason

When the mastoid region is examined, behind the processproperly speaking, between it and the occipital, is a sort of

mastoid scale, bounded by a vertical line goingfrom theparietalslope of the superior border of the temporal to the digastric

fossa It is on this line orbehind it that the mastoid foramen

is found It is on the inner surface of this scale, behind the

pyramid, that the lateral sinus descends, below its elbow, the

bend corresponding to the asterion, thatis to say at the junction

of the occipital, the parietal and the mastoid, and encroachingmore or less on the postero-inferior angle ofthe parietal. There

of mastoids, and found that they could be classified into three groups :

(1) those inwhich the lateral sinus will not beencounteredinanoperation

onthe antrum; (2) those inwhichitmayormaynot bemetwith; (3) those

14 Surgical Anatomy

it isthe rule not to find any cells, but a diploic plate betweentwo compact laminae, as inthe rest of the cranial vault If thesinus was invariably to be found in this region, it would always

be very far fromthe process properly speaking, but it is enough

tolook at the inner surfaces of several crania to know that thegroove for the lateral sinus is more or less large, that its bend is

more or less high and more or less forward, not only in one

subject and another, but on one or other side; and the rule is

that the lateral groove is larger and deeper on the right side

than the left.

Suppose now a very large and very deep groove, and we

understand perfectlyhow in horizontal and transverse projection

it can be verylittle behind themeatus, or may even be in front

of it at this level. But would that be to say that the antrum

was notin its place? Absolutely not, for it can well be lodged

in the thicknessat thebase of thepyramid In these conditions

it isvery evident that ifa probe were drivenin at the spot where

we should describe the antrum, it would directly puncture thesinus instead of entering the cranium in front and 'within it.

But, before reaching there, the probe would pass through the

antrum; that is to say, the surgeon, operating at the seat ofelection and with care, would meet with a cavity, and from thattimewould be prepared, if he remembered it, for the possiblepresence of the sinus; the deep wall of this cavity ought not to

be attacked save with greatcaution and underspecial indications

(vide p 47).

This anatomical arrangement, then, is far from being

respon-sible for all the dangers which have been attributed to it, and to

declare that amastoid is impossible ofopening,it isnotsufficient

to have proved, in anintact cranium, thefalling forward of thesinus ; it is still necessary, by a horizontal section at the level

of the spine of Henle, to have demonstrated that there is no

cavity between the cortex and the sinus at the field of operation

It is this proof which is too often made an excuse, for

anatomi-cally it demands the sacrifice of theskull examined,, and in the

live subjectthe surgeon who involuntarily opens the sinus hasa

tendency, too natural for blame, to remember an anatomical

arrangement which he will repeat soonerthan accuse himself of

clumsiness (vide Fig 30).

Now, this absence of the antrum at the seat of election, the

cells being reduced to deep petrous cells, separated from thecortical by the too forward sinus until perpendicular to the

Surgical Anatomy 5

meatus, I have only proved anatomically in two instances of

Millet (vide Fig 30) ; and I have operated, without, moreover,

woundingthe sinus, upon two children brother and sister in

whom it appeared to exist, so far as one can judge in the livingsubject

This discussion has a real importance from a practical point

of view It isvery certain indeed and I cannot do betterthan

quote the phrase so clearty expressed by Eicard that '

theposterior half of the mastoid is dangerous on account'of its

vicinity to the lateral sinus, but the danger diminishes in portion asone leaves the base to approach the summit of theprocess.' But several operators have concluded that, becausethe anterior part of the base can bealso dangerous, the summit

pro-ought to be opened; this is to attack the bone in a region

where the cells are often wanting; it is torisk not finding pusand to pass severalmillimetres nearit.

In realityit is necessary to look for the cells where they are

constant, that is to say in the petrous bone, properly speaking;

and by searching among the petrous cells, in the base of the

mastoid and in front, we can nearlyalways find the antrum bymeans of very distinct external landmarks

Theprecedingmethodbecomes wrongif,onaccount of chronic

inflammatory processes, the cellular system of the eburnatedmastoid becomes obliterated, or nearlyso. Butthen,ifoperatedupon, the opening is indicated, with the antrum, of the aditus

andthe tympanum, and from that timeit is always easyto find

a natural cavity by beginning with thetympanum and following

Stacke's method

An examination of the figures shows well that in the young

child the sinus, however forward (Fig. 45), is always a good

way from the antrum (Fig. 46) In the adult we have never

found more difficultythan in the case ofFig 54; and

neverthe-less in that case also the operation was well effected. In the

cadaver the sinus has always been foundvery hollowed (Fig 51)

or nearly level. For the child the sections 20-23 and 27-30

should be consulted

The Attic and Aditus

I have not the least intention of describing in detail the

anatomy of the tympanic cavity : topographical anatomy

in-terests me solely as indivisible from surgical procedures. With

the foregoing knowledge, the surgeon is, in measure, to study

Surgical Anatomy

the operative procedure, which allows him to open the cells

of the mastoid and to reach as far as the drum by passing

through the aditus

But Isay and this indication is not the onlyone that veryoften, in chronic suppurative otitis cases, it will be more conve-nient toreach the aditus by its tympanic entrance and notbyits

mastoid exit. This is Stacke's operation, and to understandit, it

is necessaryto know the exact arrangement of the upper part

of the 'drum, called the '

attic

'

in modern otological language.The tympaniccavity is hollowed out in the base of the petrousbone, between theexternal meatus and the internal ear It is

customary to compare it to a slightly raised drum, whose two

bases are depressed in the centre, and which is described as

having two surfaces and a circumference, arbitrarily dividedinto four walls

The inner or labyrinthine surface has not any interest from

an exclusively operative point of view It is altogether wise with the outer or tympanic surface

other-The important fact to retain is the following: If, as I amgoingto do, the tympanic cavity be compared to a cylinder, and

if the outer wall be considered as pierced by a large openingwhich is closed by the tympanic membrane, it must be acknow-

ledged that this opening does notoccupythewholesurfaceofthe

wall,but that, aboveand below,above especially, it issurrounded

by a bony frame of considerable size It is like a door in which

the threshold is raised by a step above the floor, and whose

lintel is placed at a considerable distance from the ceiling. Inother terms, when the membrane is seen at the bottom of theexternal auditory canal,one oughtto be warned ofwhatis below

thismembrane; the bonycircle into whichit is set limits a little

gutter, which is, above, a relatively large vault ; it is this vault,this epitympanic cavity, this cupola, which modern aurists are

accustomed to call the '

attic.'

The attic is,then,the part ofthe tympanum situatedabove an

imaginaryplane passingthrough the short processof the malleus

The outerwall, thatwhich separatesit from themeatus, is closed

below for a slight height above the headof the malleus enclosed

in the tympanum, by the membrane of Schrapnell ; above this

membrane by a bonywall which Walb calls the pars ossea,but

which is better named, with Gelle, the wall ofthe cabin of the

ossicles (le mur de la logette des osselets, outer attic watt}.

The in of the chief

Surgical Anatomy 17

that is to say,thehead and neckofthe malleus, the shortprocess

and the body of the incus

The internal wall of the attic (part of the labyrinthine wallsituated above the fenestra ovale)only possesses surgical interest

byits relations with the transverse semicircular canal and the

facial, which is there projecting; the posterior wall is occupiedalmost entirely bythe tympanic orifice of the aditus ad anti-urn,

5 to 6 millimetres high, usually larger above than below It

is justnear this aditus, of which I have already pointed out the

relations with the facial and the semicircular canal, that theshort process of the incusis seen resting almost on its floor.

Abovethe aditus and the attic is the roof of thetympanum.

This tegmen tympani separates the middle ear from the middle

cerebral fossa More or less marked according to the subject,the petro-squamous suture can be seen there, sometimes large

enough to constitute a perfect '

dehiscence'

of the roof. Then

the dura mater and the tympanic mucosaare in contact

It will beeasy, in Figs 16-20, to study the mode of junction

between the squamouspart of the temporal and the petrous,the

former serving, in short, as a cover, above and outside, to thecavities of the middle ear. Fig 18, particularly, shows that in

ayoung enough subject thesetwo bones canbe isolatedfrom oneanother without fracture

The mode of union between these two bones at the cerebralfossa is especially interesting The plate of the petrous hidesthat of thesquamous, and the connection is much more exten-sive as the subject is older The result is that the internal

petro-squamous suture passes farther outward, and ends by

corresponding with the upper surface of the auditory meatus

The definite gaps are, in short, arrests of development; theyfavour the developmentof meningitis and brain abscess

I shall not further lay stress on the topographical anatomy of

theattic in this place; Iprefer to consider the technical details

when I shall discuss them in speakingof Stacke's operation

18 Operative Procedures

II

OPERATIVE PROCEDURES

I SHALLstudy successively :

1. Simple openingof the mastoid

2. Opening themastoidand the tympanum.

3. Stacke's operation, pure or completed by opening the

mastoid

4. Opening the cerebral or cerebellar fossaeof thecranium

I. Opening the Mastoid

Choice of Operation Veryvariousmethodshave beendescribedfor openingthe mastoid From the preceding anatomical facts

it follows that our choice should be guided bythe following siderations : (1) the first task should be tolook forthe antrum;

con-(2) this search should be made by the post-auricular route;

(3) the post-auricular incisionshould bemadeasclose as possible

to the pinna; (4) all the bony cavities, in which pus may belodged, should be widely opened

1. The antrum should be our first object: of all the cells

which we have studied anatomically, it alone is constantlypresent and nearly constant in its relations I consider it is

necessary to abandon Delaissement's method, which consists in

opening the cells at the tip. Delaissement gives as the first

reason that those cells are the largest; that is possible when

they arepresent, but oftenthey do not exist. He says, further,that it is necessaryto open the abscess at the lowest point ; as amatter of fact, it is necessary to at once bring to light the

antrum and all the other cells, as I shall presently explain He

insists upon the distance of the sinus at this level, and thatis,

without doubt,his true reason ; the truth is, that it is necessary

tolearn toavoid the sinus at the base of the mastoid, and my

statistics prove that it is possible to do so.

2 It is againfearofthe sinus that has influencedthesurgeons

who have proposed and practised opening the antrum by theexternalauditory meatus The operation, doubtless,presents no

difficulties; but if, by this route, the sinus and the middlefossaare faraway, the facial nerveis very liable to be wounded On

the other hand, all the cavities of the mastoid cannot be well

antrum is reached at but on

Operative Procedures 19

account of the facial, the opening cannot be extended beyond

this point; the bone cannot be excavated behind when it is

diseased in that region. It is enough to look at a specimen to

thoroughlyconvinceone'sselfthat the dressings aredifficult,and

made by a narrow orifice, which is scarcely accessible even toa

probe

3. None of these objections hold in the case of the auricular route, in which the sole danger is thewounding of thesinus But this injury must be exceptional in the hands of a

post-skilled operator, and the first condition for its avoidance is toreject absolutely the cutaneous incision adopted by Poinsot.This author advises an incision parallel to the concha, fromwhich it is separated by an interval of 10 to 15 millimetres

Trace this incision,andbetween the lipsthrust a pointer dicularly into the bone, you will stand a great chance of goingstraight into the sinus And, let it be thoroughlyunderstood,there will be no question of seeing the bony landmarks upon

perpen-which I have insisted above To see them it is necessary toincise in the post-auricular groove, andthen to push forward the

pinnawith a rougine until the commencement of the funnel ofthe meatus is seen, for the auricle stretches behind over theanterior part of the mastoid

4. The cellular system is very complex and very variable;

often certain groups only communicate with the antrum by a

very narrow opening. The only method capable of insuring an

effective drainage consists in successivelybreaking down all the

bonylaminae which separate the cells fromthe antrum andfrom

the exterior: to create, consequently, a single cavity, widely

open behind the meatus.

Such are the generalprinciples; let us see their application.Operative Technique Ishallfirstdescribe the typical operation

whichis practised on the cadaver, or on the living subjectwhen

the skin, subcutaneous tissues, and bony cortex are healthy

The skin incision should be tracedin thepost-auriculargroove,the pinna being turned forward by an assistant,or by the left

hand of the operator. It should measure the length of the

mastoid and be recurved above the meatus To get plentyof

light, aposteriortransverse incision can be made at the base of

the mastoid, crossing the first ; a practised operator can easily

dowithoutthis incision, which leaves a visible scar, whereasthe

pinnaentirely hides the scar inthepost-auricular groove.

The incision is at once continued boldlydown to the bone, at

22

have been freed.

The next thing to be done is to laybare the whole region of

the mastoid and meatus by means of the rougine Without

detaching the membranous meatus, the rougine is pushedtowards the bony funnel, so as to see the contour thereof with

its upper boundary and the spine of Henle The base of the

mastoid and this point should be laid bare. For severalseconds, when the whole field of operation is thus brought to

view, there is everyfacility for using the pressureforceps on the

Hps of the incision

Beyond theirhaemostatic function,theseforceps, tothenumber

of two or three to each lip, act also as automatic retractors;they should be allowedto fallexternally, and overtheir rings on

either side an aseptic compress should be placed of sufficient

weight,so that it may at once keep theforceps down and protect

thefield of operation

This done, the bone is distinct at the bottom of the sponged

and gaping wound, andthe bony landmarks can be clearly seen

and verified with the nail, the temporal ridge, the spine ofHenle, if the subject is not very old the line of themastoido-

squamous suture, andthe posteriorand superior boundaryofthe

bony meatus To make out the latter well, one need only

protrude a channelled sound introduced into the membranous

meatus.*

With these landmarks the antrum may be found with

certainty

The only suitable instrument is the cold chisel, driven by a

small leaden mallet I believe it is unnecessary to insist upon

this point, judging by to-day; day by day the partisans ofgimlets, trephines, drills, etc., grow fewer

In the adult, one should work in an area about 1 centimetresquare, situatedbehind the upperpart of themeatus, levelabove

with the supra-mastoid ridge orthetemporal line(Figs. 1and2).

A sharp chisel is taken, about 1 centimetre broad, and applied

very perpendicularly to the bone, 5 millimetres behind the

* When this is done, it will be found veryuseful to pass a strip of gauzethroughthemembranousmeatusandoutbythewound,to act as a retractor.

Translator.

Operative Procedures 21

meatus marked by the spine of Henle, parallel to the ference of the meatus, with its superior angle as high as the

circum-upper pole of the meatus With the left hand the chisel is

steadied solidly to prevent it from moving or

slipping, and, bytwo or three very sharp strokes with the mallet it is made topenetrate 2 or 3 millimetres deep. One works similarly on theupper border of the square, viz., under the supra-mastoid ridge,

then on the inferior border, i.e., I centimetre below the ridge

andparallelto it. For these two strokes, equally, the chisel is

held perpendicular to the bone

^

There now remains the posterior side of

the square: it is theside made dangerous

by the lateral sinus, ^^^ . a

although thedangeris

rare at 15 millimetres

behindthemeatus To

finish the area, the

chisel must no longer

be held perpendicular

to the bone, but

suffi-ciently oblique at

about 45 degrees

and in several strokes,

always very sharp, the

square of cortex is

raised (Fig 3).*

Often, especially if

the cavities are full

of pus and enlarged

by rarefying osteitis,

the antrum will be

quickly found underthe square

j-.m+r.

FIG 1.

The area of operation and its relations to the spine of Henle (H), the two ridges, supra-mastoid (c.s.m.) and mastoido-

squamous

meatus(Cond.).

But often, also, it is necessary

to go deeper This is done with care, always with the chisel

and mallet, millimetre bymillimetre, pushing the work equally

on all sides of the square in depth, but not making it wider

From the depth of about 1 centimetre one becomes more and

* The raising of this square of cortex in thispositionwould, I think, be

takenexception to by most otologists in thiscountryas being too far back.

MostEnglish surgeons prefer to commence their excavation nearer to the spine of Henle (or supra-meatal fossa). Personally, the square area of

operation in which I commence my opening of the mastoidisonewhich,

similar to that ofBrocain its dimensions, is placed higherandmoreanterior,

including the spine of Henlewithin it, its anterior face beingformed bythe

meatus Translator.

22 Operative Procedures

more cautious, because of the facial below and in front, and

the sinus behind, and the square should be transformed into afunnel; chiselling above, in front, and within, working in con-sequence towards the region of the aditus For this, a chisel

1 centimetre broad is too large, and it is necessary to use asmallone of a breadth of about 4 to 5 millimetres

These small chisels are used exclusively in the child under

fifteen years, especially under ten, and the same operative

method is employed as inthe adult, with this differ-

ence: that the area of

attack should be only 5millimetres square and

should be situated 3

milli-metres behind the meatus

If neither the spine of

Henle nor the

supra-mas-toid ridge is seen at thisage, the horizontal tangent

from the superior pole ofthe meatus can be taken

as the upperline.

It is in an accessof

pru-dence that I have .insisted

on the other landmarkswhich distinguish certainpoints of the bone As

a matter of fact, the

supe-rior pole of themeatus is

anffi cipnt and it is luckv

O UlU.dOl.LU* dllll AU JLC5 1LIU.1V*y

FIG 2.

The same figure with suchlandmarks as

incision, the pinna (Pav.) being turned that this is SO, for in the

This contingency is, it is true, altogether exceptional It is

very rare in the young child (the cortex being very thin and

porous at the level of the antrum, as I have already said) that

an donebeforetheformation ofa

Operative Procedures 23

Paa

at the bottom of which is found a bare point of bone It is

very rare, also, that the bare portion does not exist as regardsthe antrum at the placeof election,aboveand behind themeatus

If by chance these two rarities are combined, one is still easilyguided by the spongy spot described above (see p. 54, Fig. 39).

In the child under one year, in excavating the friable point,

normal or diseased,of thecortex covering the antrum,the tion can always be done simply with the curette

opera-It is the only case in which Ido not advise the use of themallet and chisel, provided that: (1) the curette is perfectlyappropriate, small,hollow, strong,and sharp; (2) the bonypointfor attack is rigor-

ously kept to; (3)

one acts with

pru-dence and directs

the cutting part

above and in front

towards theaditus

The precise spot

has always shown

me, in the young

child, the

patho-logical baring at the

seat of election of

the antrum At a

later date it is not

the same, and it is

important to know

this in cases where

anoperation isdoneaftertheformationof an abscess orafistula.

It would seem at first sight that one ought always to enter atthe point, friable or perforated, of diseased bone, and, as one

progresses, to allow one's self to beconducted to theantrum by

the lesions seen It is thus that one is exposed to operativecomplications, to perforation of the sinus especially. Often

enough, as a matter of fact, the pathological opening is very

much back as regards the sinus; and, on the other hand, one

does notknowwhether the deep bony wall of the lateral groove

is still present; as it is not rare that, if one seeks to enlarge thepathological opening with an instrument, the first cut breaksinto the sinus, and anexploration with a probe ought to be suf- ficient for that

FIG 3.

The oblique position of the chisel which, for the posterior track, removes the cortex previously

marked out over the three sides of the area of

operation Pav., the pinna turned forward, allowing the entranceto thebony meatustobe

seen. Otherlettering as hipreviousfigures.

Operative Procedures

Pav

The absolute rule in operative surgery ought, then, to be not

to primarily occupyone's self with lesions of the cortex, barebone, or fistula at least, those that do not correspond to the

well-marked seat of the antrum every ivell-conducted operationshouldbegin with thediscovery oj theantrum at theseat ofelection.

Therest of the time is occupied in laying lare all the secondary

cells, without leaving any cul-de-sac where pus can collect.

Now is the time when the surgeon should remember theanatomical facts upon which I have already insisted : for to

leave a cell ignored is to allowthe symptoms to persist, and to

have to do a secondary

opera-tion. The practiceis ordinarilyvery simple, for the cells com-municate freely among them-

selves, and the curette by itself

breaks away,so tospeak, severalthin septa. But when the mas-

toid can be said properlyto besclerosed, it must not be con-cluded that the antrum alone

exists, and also, when no

appre-ciable cell can be found in thebase, a suppurating cavity may

be present at the tip, as Ihave

twice seen These anatomical

The antrum being opened, it is variations merit attention, and

enlarged with the chisel held to give an account of the Way

~

/ TTI

'

i in which a surseon should act

the cortex, guards the deep parts it seems best to refer him tofrom accident. Otherlettering as

otorrhosas, which are often accompanied by consecutive

eburna-tion of the mastoid, are always to be mistrusted But it must

not be forgotten the figures bear testimony that, without

any previous otorrhcea,these embarrassingdispositions maywell

be congenital.

An expert operator can work without trouble with a small

spoon-shaped curette, but Stacke's protector gives absolutesecurity The beak of the instrument is inserted under the

Operative Procedures

sinus; and on this beak, which prevents allviolent penetrationinto the deep parts, towardsthe sinus or towards the facial, the

bony septa thus marked are destroyed by short blows on the

chisel. When the curette

touches everywhere on

smooth bone, limiting a

single cavity, on the wall

of which the* beak of the

protector or the probe no

longer finds any

diverticu-lum in whichit becomes

en-gaged, the surgeon

stops-safe above, in front, and

within where the mastoid

exit of the aditus, easy to

catheterize, is found

The bony cavity can only

be examined when it is

per-fectly freefrom blood This

is easy to attain if at first

complete stoppage of the

bleeding of the soft parts

FIG 5.

Antrum and secondary cells are widely opened Ad., aditus ad antrum, the

relations of whichto the supra-mastoid

ridge are seen(c.s.m.); spine of Henle

(H), and entrance to bony meatus

(Cond.), visibletogetherbythe turning

forwardof thepinna(Pav.).

is assured, and if, on the

other hand, with tampons

of dry sterilized gauze,

tem-porary pressure on the

ooz-ingbonysurfaces is used

I never wash the wound

I have given up immediate

union, and I confinemyself to packing the cavity with iodoformgauze With a well-arranged tampon anda compressive dress-ing, it is needless to tie the vessels of the soft parts

In making the dressing, apacking of iodoform gauze should

be placed in themeatus

II. Opening the Mastoid and Tympanum.

This operation comprises the following steps: (1) Skin

incision; (2) exposure of the bone; (3) finding the antrum and

excavationof the mastoid : (4) opening ofthe aditus and attic.

1. The skin incision is the same as in the preceding case, withthedifference that it is longer and recurved abovethe pinnaover

the fossa If a fistula is or an abscess behind

26 Operative Procedures

the post-auricular groove, after having traced in the groove thetypical incision, a transverse cut is added, passing through the

fistula or bisecting the purulent pocketat its broadest part.

2. The exposure ofthe bone comprises here, beyond that of the

wholemastoid, thatof the lower part of the temporal fossa and

the meatus To effect the latter a straight thin rougine is

inserted, with which the posterior wall is separated, inferior and

superior to the membranous meatus, up to the tympanic ring;

then, at this level, right to the bottom of the osseous canal, the

cutaneous tube is cut, and, in going back along the surfaceagainst the anterior bony wall, the membranous meatus is

brought down entire. Auricle and meatus are then turned

for-ward, held in place by forceps covered by an aseptic compress,

and from that time thewhole bonypart of the region is seen;

mastoid, bonymeatus, and tympanic frame, with what remains

of themembrane.

Such operation is only done, as a matter of fact, in chronicmiddle-ear suppurations, in which the membrane is perforated

or largely destroyed

To obtain a clear view it is first necessary, as I have already

said, to obtain a perfect cessation ofbleeding fromthesoftparts,

without which the blood accumulatesinthedependent parts,and

packing is made with a plug of dry aseptic gauze, which is kept

in place during the search for theantrum

3. Finding the antrum andexcavating tlie mastoidiscarried outexactly as has been saidabove, at the seat of election,whichwill

be the seat of appreciable external lesions It is in the actualcase especially that I would insist upon this precept, for it isinchronic mastoidites and otites, to which alone the complete

operation is applicable, that these lesions are usual

These lesionsare not the only ones The mastoidundergoes,under these conditions, more or less profound alterations; but

in spite of this, without enteringinto a descriptionofthevariouscases which may be met with, it is possible to give severalgeneral precepts of operative surgery

It is in caseswhere the work is all done that a large cavity,

goingnearly into thetympanum,widelygaping underthefistula,

is found The caries has eroded the wall of the attic, theposteriorwall ofthe meatus, andthe curette soon findsproof of

several small friable bony spots

Sometimes the contains sequestra of more or less size.